Rotary pump



Nn. 623,605. Patented Apr. 25, |899.

E. W. G.' C. HFFMANN.

ROTARY PUMP.

lication led Apr. 1, 1898 Unire Smarts afrnnr Ormes.

ERNST VILHELM GUSTAV CARL HOFFMANN, OF CHARLOTTENBURG, GER- MANY,ASSIGNOR TO THE SIEMENS da HALSKE ELECTRIC COMPANY OF AMERICA, OFCHICAGO, ILLINOIS.

ROTARY PUP.

SPECIFICATION forming part f Letters Patent N0. 623,605, dated April 25,1899.

Application filed Aprill, 1898. Serial No. 676,081. (No model.)

To au whom, it may concern: said shaft is rotatably mounted. Upon the Beit known that I, ERNST VILHELM GUS- eccentric h is disposed the ring orcylindrical f TAV CARL HOFFMANN, a subject of the Empump part e, withinwhich said eccentric is r peror of Germany, residing at Oharlottenfreeto rotate, the two parts forming au ecburg, Germany, have inventedacertain new centric-piston f. Mounted upon the upper 55 and usefulImprovement in Rotary Pumps, side of said ring is the upright g, havingits (Case No. 149,) of which the following is a head rounded, which isadapted at all times full, clear, concise, and exact description. to bemaintained in close engagement with i My invention relates toimprovements in the left wall of the supplemental chamber xo rotarypumps, and has for its object the proc by means of a spring-like tongue71 also 6o vision of means for securing a more efficient mounted uponthe ring e and bearing against pumping or exhausting action than hasbeen the right-hand Wall of said chamber. The attainable hitherto inpumps of this class. upright g is centrally bored to receive the It hasbeen found in practice diflicult or Well three rods t', which loosely twithin their re- I5 nigh impossible to secure any considerable s pectiveopenings in said upright. 65 rarefaction of air or other gas when rotaryIt will be understood that the several movpumps were employed asexhausters, and I able pump parts mounted within the houshaveaccordingly devised means for obviating t quite closely the walls oftheir respecing this defect. The reason for the unsatistive chambers. Onthe upper part of said zo factory operation above alluded to is thathousing is mounted the oil-cup 7e, and from 7c means have not beendevised previously for supplemental chamber c oil-overilows cperinsuring in a pump of this class a packing mit the oil to pass intothe wells a, disposed that is sufliciently tight or'close fitting toseupon either side of and communicating with cure the necessaryrarefaction when the pump the exhaust-chamber c. The inlet or eX- is inaction. hausting pipe Z opens into the chamber c be- 75 I will describemy invention as applied to neath the head of the upright g. a type ofrotary eccentric pump wherein my The operation of the pump will nowbereadimproved lubricating packing is employed. ily comprehended. Theparts within the eX- This type of pump may be brieflycharacterhaust-chamber having been previously thorized as consisting ofan eccentric pump part rooughly lubricated and the wells a being par- 8oy tatably mounted upon the driving-shaft Withtially filled with oil, therotation of the shaft 1. in the exhaust-chamber, with which chamber andeccentric in a contra-clockwise direction and pump part are associatedmeans for insurwill serve to exhaust the air within the chaming freelubrication of the said parts,whereby ber c and through thecommunicating inlet Z.

ahighly-efticient exhaustingactionissecured. The surplus oil within thechamber will be 85 The above device, in connection with which pressedupward with the air into the supple- Iwi'll now explain my invention,will be more mental chamber c' and pass the spring or readily understoodby reference to the accomtongue h, which readily permits the upwardpanyingdrawings,formingapart of thisspecipassage of the oil and air andserves as a 4o fication, whereinvalve to prevent their return. Thespring or 9o Figure l is a transverse sectional view o tonguemaintaining the upright in close ensaid pump, and Fig. 2 is alongitudinal secgagement with the left wall of the chamber tional viewthereof. prevents the entrance of air to the left side The same lettersof reference are used to of the exhaust-chamber. The surplus oil indesignate like parts in both of said gures. the supplemental chamberwill pass through 95 Power is supplied to the driving-shaft a, theoverflows and into the wells d, from which i upon which is keyed orotherwise secured the it returns to the exhaust-chamber andmaineccentric l), mount-ed within the exhaust or tains the packingbetween the moving parts pump chamber c. The pump housing or casand theWalls of said chamber, being forced ing d provides end bearings a a',wherein the therein through the bearings by reason of the loo vacuumproduced in the said exhaust-chamber. The oil is also forced downwardthrough the openings in the upright, the reciprocating movement of' saidpart serving to move up and down the rods i, which are loosely fitted inthe said openings, and force the oilbetween the eccentric and itsencircling ring, from whence it passes to the sides of the eccentric,thus assisting in maintaining the parts sufliciently lubricated. Forconvenience the oil may be supplied to the device, when desired, bymeans of the oil-cup 7e. The pressure of the external air, it will beseen, materially assists the passage of oil through the severalcommunicating openings to the exhaust-chamber.

From the above it will be seen that in the normal operation of the pumpthe complete circulation ofthe oil will be maintained, which secures atall times for the device a very high efficiency. A very thick or heavyoil preferably is employed in the rotary pump above described, althoughother fluid packing or heavy lubricants may be found efficient for someapplications of said pump.

Various modifications 0r departures from the device herein described maybe made without departing from the spirit of my invention.

I accordingly claim as new, and desire to secure by Letters Patent, thefollowing:

to supply oil to the pump parts, and an overiiow or return passageconnected with the discharge-opening of the pump, whereby the lubricantor fluid packing is circulated and freely supplied to therelatively-moving parts, substantially as described.

2. In a rotary pump, lche combination with the exhaust-chamber c, of theeccentric-piston fmounted therein upon an actuating-shaft a, an uprightg adapted to maintain the exhaustchamber closed to the external air,oil-overflow c", and a well c communicating therewith and With theexhaust-chamber, Whereby a iiuid packing or lubricant is circulated and.freely supplied to the relatively-movable pump parts, substantially asdescribed.

3. In a pump of the class described, the combination With anexhaust-chamber c, of an eccentric-piston f mounted therein upon anactu-.

ating-shaft a, an upright g provided with rods e' loosely mounted inopenings in said upright and adapted to assist in lubricating theconnected piston, a valve part 7L, oil-overflows c, andlubricating-receptacles a" communieating with the said overiiows andwith the exhaust-chamber, whereby a fluid packing or lubricant iscirculated within the pump and freely supplied to the relatively-movablepump parts, substantially as described.

In witn ess whereof I hereunto subscribe my name this 7th day of March,A. D. 1898.

ERNST WILHELM GUSTAV CARL HOFFMANN. Vitnesses:

PAUL ROEDIGER, C. II. DAY.

